Pressure-responsive circuit controller



Jan. 1, 1924 1,479,580

T. E. BARNUM ET AL.

PRESSURE RESPONSIVE CIRCUIT CONTROLLER Filed April 2'7. 1921 INVENTORS. mgen/mm1,

ATTORNEY Patented Jim. i, 1924.

,UNITE-D, STATES PATE'NUT oFFici-z.

THOMAS E. BARNUM, OF WAUWATOSA, AND CLARENCE T. EVANS, OF MILWAUKEE, WIS- CONSIN, ASSIGNORS TO THE CUTLER-HAMMER MFG. OO., OF MILWAUKEE, WISCON- SIN, A CORPORATION 0F WISCONSIN.

PRESSURE-RESPONSIVE CIRCUIT CONTROLLER.

'Application led April 27, 1921. Serial No. 465,065.

To all whom t may concern:

:de it known 'that we, THOMAS E. BARNUM and CLARENCE T. EVANS, citizens of the lUnited `States, residing, respectively, at TNanwatosal and Milwaukee, -in the county of Milwaukee and State of Wisconsin, have invented new and useful Improvements in Pressure-Responsive Circuit Controllers, of which the ollowin is a ull,.clear concise, and exact description, reference being had to the accompanying drawing, forming a part of this specification.

This invention relates to pressure responsive circuit controllers and particularly to controllers of the ldiaphragm type.

Such controllers as heretofore constructed have been in many instances objectionable by reason of uncertainty of operation thereof and also by'reason ofdisproportionate space requirements, together with inaccessibility of parte which inherently tend to require more or less frequent ins ection, repair or replacement. Further, W ere metallic diaphragme are employed the same tend, in the absence or special provision, to deteriorate rapidly and to failfollowing a relatively brief period of service whereby again'tlie reliabilityof the device is seriously curtailed.

The present invention has among its ob jects that oi'overcoming Ithe aforementioned dilliculties and disadvantages of suoli controllers as heretofore constructed.

Another object is that ot' providing an exceedingly simple, durable and reliable controller comprising a minimum-number of simple and rugged parts compactly arranged and readily accessible.

Aanother object is that or providing a cornbination and assembly of parte snch that maximum mechanical effect is attained particularly-as 'regards thosefunctions wherein such eiiciency is most desirable and without sacrificing other desirable lfeatures.

Another object is that of providing novel and improved means for minimizing deterioration oi3 'the diaphragm element to thereby increase the reliability and length' of service of the device.

Other objects and advantages will hereinafter appear,

- In the accompanying drawing wherein is illustrated an embodiment of the invention, Fig. 1 is a vertical sectional view thereof; while, y

Fig. 2 is a horizontal sectional View of the same, substantially on line 2--2 of Fig. 1.

Referring to the drawing the same illus- In practice the fixed contacts, each pro-` vided with suitable circuit connections, arev ermanently and rigidly secured to the housing section 10, the shaft 9 being also pivotally supported within said housing section. Said shaft is preferably constructed hollow and of .a length such as to permit ready insertion thereof within said housing section, ka rod 12 being passed through suitable openings in said housing section and through the bore of said shaft for pivotal support of the latter, said rod being secured in place by Cotter pins or otherwise.

An operating cam 13 is rigidly secured to said shaft preferably in a relation between the aforementioned contacts 7 and 8 as illustrated. Said cam is preferably provided with a dependent lug 14 adapted to coact with a flush portion 15 ot the casing section l() for limiting oscillation of said shaft in a direction corresponding with opening movement of the switch contacts. l An elongated lever 16 is pivotally mounted within and upon said housing section lll) special construction and preferably comprises substantially parallel but' laterally odset terminal portions 18 and 19conneoted by an intermediate portion 2G which extends substantially at right anglesl thereto and sub. stantially' parallel tothe direction of said movable contacts. The terminal portion 18` of said lever lis furthermore divided as shown for a purpose to be hereinafter ex.- plained. The free end of said lever carries thereon a pivotally mounted dependent lever 21 normally occupyinga position substantially parallel to that of the intermediate section of said lever 16 and being of a length approximately equal thereto. iA roller 22 is carried as illustrated adjacent the free lower terminal portion of said lever 21 in a relation suitablefor direct co-operation with the cam 13.

'lhe arrangement of the foregoing parts is such that the shaft-9 is located adjacent the central portion of a rectangle, three sides of which are formed by the `dependent lever 21 and the terminal portion 19 and intermediate portion 20 of lever 16, the cam 13 extending toward said depending lever 21 and being located within the vertical projection of the terminal section 19 of said lever 16.

A tension spring 23 terminally connected to said levers as illustrated serves to bias the roller 22 against the cam 13. Said intermediate ortion 20 of lever 16 is furthermore provi ed with an elongated recess 24 having terminal shoulders I25 and 26 adapted to co-operate selectively with 'a lug 27 carried b said housing sect1on 10 to thereby limit swinging of said lever in either direction. Said housing section 10 is provided at a point below the divided portion of the lever 16 with a relativelyenlarged opening 28, said opening being in practice jcovered by a llexible diaphragm 29 preferably metallic in4 character, secured across said opening by means of a flared header 30 clamped 4 to said housing section by means of suitable boltsv or otherwise. Said header member is further provided with an exterior o ening 31 `for subjecting the space between t e diaphragm and said header to fluid pressure.

A piston element 32 of 'a size materially less than that of the opening 28 is arranged within said opening above the diaphragm 29 in arelation to be liftedb 32 and the upper portion of said housin section. In practice the upper end of said said dlaphragm, said4 piston being provi ed with an' 'Le'raeeo spring'V is preferably -received and retained within an adjusting nut 35 screwed within said housing section, said nut thus providing for exterior adjustment of said spring, The upper side of said piston element is further provided with a suitable recess 36- arranged substantially centrally thereof for retention of the lower end of said spring.

The lower side oit said piston element is preferably provided with a substantially conical recess 37 adapted to receive a rounded head portion 33Ex of a stud 33 carried centrally of the diaphragm 29,' thus adording an open universal pivotal bearing between said diaphragm and said piston eleinent, the point 39 of pivotal attachment of said .piston element to the lever 16 being materially oifset laterally from said bearing as illustrated.

The cam element 13 is preferably of special construction and comprises a pair of substantially straight exterior meeting at an angle. The direction of such surfaces is moreover such that the bisector of the angle therebetween passes above the surfaces lf point 17 of ivotal support of the lever 16 as illustrate for a pur ose to be described.

Flexible and rererahly resilient gaskets 40-41 compose of rubber, leather, paper, or the like are arranged respectively upon the'upper and lower sides of the diaphragm practice to increase the period oi reliable f service of the diaphragm more than ten-fold, and without limitation to any definite .theory to account for such edect, it is be'- lievedthat the yielding or resilient nature of said gaskets permits the diaphra irwhen moved axially to assume the articu ar forni 'determined bythe stresses inducedutherein 'by the o erating force without compelling lthe diap ragm to assume the form oi the 'metallic parts contiguous thereto whereby thebending strains upon the diaphragm are greatly reduced. v

Similar gaskets 42 and@ are also preterably located in the central portion of the diaphra and clamped in place by the stud 33 as il ustrated and for similar pur enses.

The second housing section 11 1s a apted to be secured to the section l() by means of screws or in any other desired or preferred manner, said housing sections being prefer'- ably articulated upon a confunon plane and said plane being se located with reference to the enclosed parts that upon simple removal of the section 11 the switch contacts and .connections as well as the aforedescribed cam, roller and spring. 23 together with most of their associated parts are rendered readily accessible.

Further the aforedescribed method of mounting the shaft 9 provides for readyremoval and replacement orinterchange of saidshaft together with the parts supported thereby. Also the aforedescribed manner of mounting `the iston element 32 upon the diaphragm stud) 33 permits ready removal of the lever ltogether with all of its associated parts upon simple disconnection thereof from its pivotal support 17 follow? ing withdrawal of the spring 34 by removal of the nut 35, removal of the diaphragm 29 and its associated parts not being required.

The operation of the device may be described as follows, the partsl being in the position illustrated in full line in Fig. 1 and the pressure below the diaphragm being assumed insuilicient to overcomey the force of the spring 34 as adjusted. Thel stop 27 serves to preventdwnward movement of lever v16 whereby the tension of the spring 23 causes roller 22 to exert upon the cam 13 a pressure having an upward component for maintaining the switch positively closed, and also effecting bending of the contact springs 7a and 8n with consequent storing of energy therein. Y

Upon attainment of a given pressure below the diaphragm 29, the latter is forced upward with consequent upward movement y of the free end of lever 16, the spring 34:

being compressedand ,also bent or bowed due to the eccentric location of lug 33. Also the roller 22 is caused to move upwardly and outwardly along the lower surface of cam 13, the spring 23 being placed under increased tension. rlhe angle between said cam surface and the line joining the crest of the cam 4with the point i7 being relatively acute as aforedescribed, the opposition to upward movement of the lever, due to such co-operation or" the cam and roller'under tension of spring 23 is augmented.

Thus the pressure below the diaphragm 29 is required to overcome not only the opposition of the spring Sei including that due to bending or bowing thereof, but also the opposing action of spring 23x as augmented in the manner inst described.

Hence at the instant just prior to arrival of said roller at the crest of the cam the Huid pressure required to eiect further movement of the lever 16 is considerably augmented due to the special construction and arrangement aforedescribed. At the instant wherein the yroller passes the crest suoli augmented pressure is suddenly released for throwing the roller suddenly across the crest, the tension of the springs 7a and t3a being simultaneously released for effecting movement of the cam itself in the opposite considerably reduced in order to avoid undue extension of the range of fluid pressure variations required to effect operation of the device in reverse senses. Y

Thusl prior tol closing movement of the switches the contact springs 7d and 8B are not bent and hence are not adapted to the release of stored energy tending to effect.

movement of the cam itself. The spring 23 is tensioned to the same extent as fo-r open- -ing but its force is less effectively applied in resisting downward movement of lever 16, the angle between the upper cam surface and thev line between Vthe crest of the cam and the point 17 being less acute than the angle between the lower cam surface and such line.

Movement of said lever in either direcn tion is limited by the stop 27 following actuation of the switches whereas in either extreme position of the switch contacts the spring 23 is maintained under tension for upper cam surface and the line between the crest of tie cam and the center of said shaft 12 is less acute than the angle between the lower cam surface and said line. ilhus, for reasons which will be apparent from the foregoing, the energy of spring 23 is applied more effectively for maintainn ing the switches in closed position than in open position, whereby a iirm andv adeyk quete contact engagement is assured without unduly increasingy the. rangeV of fluid pressure variation rcquired'to effect operaf tion of the switches in reverse senses.

Also the foregoing special features in addition to the effects atorcdescribed furtherl serve to provide a strong and positive snap action of the switches particularly upon opening thereof. i

It is further to be noted that both the springi and the lever 16 are adapted to act directly upon the piston member 32 Wherebv the vertical dimension of the structure is practically determined by the required length of piston, diaphragm and header member.

vAlso owing to the special construction of i parts particularly of the lever 16, .the horizontal dimensions of the device are brought.

substantially within the vertical projection of the diaphragm member, thus indicating that the space requirements of the device have been reduce-d1 substantially to a minimum. v

What lwe claim as new and desire to secure by Letters Patent is: l

l.. In snapv operating means for switches and the like, in combination, an oscillatory cam having angularly related faces meeting in an abrupt crest, a roller to coact with said cam 'and supporting means for said roller comprisin a pivoted lever, a support pivoted to the ree -end thereof and carrying 'said roller at 'its free end, a spring associated with said lever and said support vto bias said roller against said cam, means to exert upon said lever opposing Jforces tendin to move' the same against the forse ofpsai spring, the faces oit said cam being so disposed with reference to the center of oscillation of said lever as to 'edect greater opposition to movement of the lever in one if @it direction than, in the other direction.

2. ln a circuit controller, the combination lwith relatively movable contacts, of operating means therefor comprising a pivoted cam positively secured to certain of said contacts, a pivoted lever, a support pivoted to the :tree end of said lever, a 'roller carried by said support for coaction with said cam, a'spring biasing said roller toward said lever and against said cam, a spring opposing movement of said lever in one direction and pressure responsive means` to actuate said lever against the force of said ispring for causing said roller to. actuate said cam for snap operation of the, switch,said.cam being designed and arranged with reference to said lever and its associated parts to augment/the force .required to'cause movement of said lever in one direction.

3. In'snap operating means for switches and the like, in 'combinatiom an oscillatory cam having angularly related lsur-face por tions meetinou inI an abruptcrest .and operating means "or said cam comprising a ref ciprocatory element to coact therewith, .a spring biasing said element against the sur-` with, a spring face of 'said cam and means associated with said spring for moving said element vacross the crest of said camin opposite directions for snap `operation ofthe cam, and'ito arrest suchmovements of said element in .relations `such that said spring is maintained under tension for holding-thecam', said cam surface portions being disposed with reference to the center of oscillation` thereof to provide di'er'ent values of the force so utilized for holding said cani following arrest of movement/oi said element in opposite directions respectively.y

4. In snap operating means for switches and the like, in combination, an oscillatory cam having angularly related surface poi'- tions meeting in an abrupt crest and operating means for said cam comprising a reciprocatory` element vto coact therewith, a spring biasing said element against the surface. of said cam and means Jfor movin said element across the crest of said cam in opposite directions for snap operation of thecam and to-arrest' such movements of said element in relations wherein. said spring is maintained under tension for holding the cam, said cani surface portions being arranged to subtend unequal angles with reference to a line determined b thefcrest of the cam and the axis of osci lation thereof lto thereby provide different values of the force utilized for so holding the cam following movement of said element in opposite directionsrespecytively.

' 5. ln a circuit controller, the combination with relatively movable contact members, of an oscillatory/cam positively secifred to certain of said contact members, said cam having angularly related surface -portions meeting in an a rupt crest, and operating means for .said cam comprising a reciprocatory element tocoact therewith, a 'spring biasing said element against the surface of said cam, means for moving said element across the crest of said cam in opposite directions for selective snap engagement and disengagement of said contact members and means to arrest such movements of "said A.element inA relations suc-h as to maintain said -spring under tension for positive 'holding of the switch in closed and in open position selectivel said cam lsurface port-ions being disposedY with reference to the center of oscillation of the cam in a manner to v augment 'f the force for maintaining the switch closed o`ver that for maintaining the same open. 6. In a circuit controller, the combination with relatively movable contacts, of an oscillatory'cam secured to certain of said contacts, said cam, having angularly related surface portions meeting in an abrupt crest,

and'operating means for said: cam compris-l ing aI reciprocatory element to coact theref biasing said element against tlievsurface o said cam, a pivoted Isupport for said reciprocatory element, means to.

exert upon said support opposing forces each tending to cause the latter to move said element in one direction across the crest of ysaid cam' witha resultant release of stored energyY for snap opening and closing of the switch selectively, said cam surface portions being arranged to subtend unequal angles with reference to a line determined by the Crest 0f the tcam and the pivotal axis of means for said cam' comprising a .recipro-l eatory element to coact therewith, a spring biasingsaid element against the surfaces of said cam, a pivoted lever carrying said reciprocatory element, means to exert upon said lever opposing forces each tending to Acause the latter to move "said element inone direction across the. crest of said cam for snap opening `and closing of the switch selectively, means to arrest such movements of said element in relations wherein said spring is maintained under tension for positive holding of the switch contacts in closed and in open position selectively and for tensioning said resilient connection upon closure of the switch, said cam surface portions being disposed with reference to the pivot point of said lever in a manner to augment the value of they energy released upon movement of said element across the crest of the cam in a direction for opening of the switch, the tension of said resilient connection tending to effect movement of the cainduring such transit or said element in switch openingv direction.

8. In a circuit controller, the combination with relatively movable contacts and an oscillatory cam having a resilient operative connection with certain oi said contacts and having angularly disposed surface portions meeting in an abrupt crest, of operating 4 means for said cam comprising a reciproeatery element to coact therewith, ayspring biasing said element against the surfaces of said cam, a pivoted lever carrying said oscillatory lever, means to exert upon said lever opposing forces each tending to cause the latter to move said element in one direction across the crest or" said cam for snap opening and closing et the switch selectively, means te arrest such movements of said element in relations wherein said spring is maintained under tension for positive holding of the switch contacts in closed and in open position selectively and for storing energy in said resilient connection upon closure ot the switch, said cam surface portions being disposed with reference to the center or" oscillation of said cam in a manner to augment the force for maintaining the switch closed over that for maintainin the same open to thereby augment the viilue of the energy stored in said resilient connection, such stored energy tending to `ranged to be compressed between said p effect reverse movement of the cam during such transit of said reciprocatory element in switch opening direction.

9. In a circuit controller, the combination with relatively movable contacts and anoscillatory cam having a resilient operative connection with certain of said contacts and having angularly disposed surface portions vmeeting in an abrupt crest, of operating means for said cam comprising a reciprocatory element to lcoact therewith, aspring biasing said element against the surface ot said cam, a pivoted lever carrying said oscillatory member, means to exert upon said lever opposing -foi'ces each tending to cause the latter to move said element in one direction across the crest of said cam for snap opening and closing of the switch selective- 1y, means to arrest such movements of said elements in relations wherein said spring is maintained under tension for positive holding of the switch contacts in closed and ,in open position selectively and for storing energy in said resilient connection during maintenance ofthe switch in closed position,'said cam surface portions being disposed with referenceto the pivot point of said lever and to the center oi' oscillation of said cam ina manner to augment the value of the energy released upon movement ot said element across the crest. ot the cam for opening ofthe switch and also to augment the force for maintaining the saine open, the stored energy of said resilient connection tending to effect reverse inovement'of the .cam during movement of said reciprocatory element across the crest oi' the y.cam

`-iii switch opening direction.

10; In snap operating means for switches and the like, in combination, a pivoted lever, a pressure responsive diaphragm, a stud carried by said diaphragm, a plunger centrally and pivotally mounted upon saidstud, said plunger having an eccentricall located lug pivotaliy connected with an intermediate portionA ci said lever, a sprin arllinger and a relatively fixed abutment for opposing movement oft said lever in one direction by said diaphragm the eccentric relation of said lug with reference to said stud serving to eect bowing of said 4spring by said plunger to thereby augment the storedv venergy of said spring.

1l. ln operatin means or switches-and the like, the combination with a flexible diaphragm to be moved with reference to an associated rigid element in response to pressure variations, of flexible means clamped between said diaphragm and said element for reducing strains in said diaphragm duel to such pressure variations.

l2. in operating means for switches and the like, the combination with a diaphra and a rigid element associated therewith to provide for iexing of said diaphragm with reference to said element in response to pressure variations, of a flexible gasket associated with said diaphragm for reducing strains therein due to4 such pressurevariations. Y

13. In operating means for switches and the like, the combination with a diaphragm and a rigid element associated therewith to provide for flexing of said diaphragm with' reference to said element in response to pressure variations, of a flexible gasket clamped the like, the combination with a flexible dia-l phragm and means, including a rigid ele-A ment clamped thereto, to provide va pressure a pressure chamber, of a flexible .gasket chamber, of'a exible gasket associated with said diaphragm and s aid element forl reducing strains set up in said diaphragm inci- 1 dent to movement thereof.

15. 1n operating means for switches and the like, the combination with a flexible diaphragm and means, including a rigid element clampedv thereto, to provide therewith a pressure chamber, of a iiexible gasket clamped between said diaphragm and said member and extendin inwardly materially beyond the zone of c amping pressure for reducing strains set up in said diaphragm incident to movement thereof.

16. lln a pressure responsive device, the combination with a flexible diaphragm and a rigid element clamped thereto to provide clamped to said diaphragm'and said element 40 to render the shape of said diaphragm corresponding with diferent pressures within said chamber substantially independent of the contour of said element.

17. 1n a pressure responsive device, the 45 combination lwith av iexible diaphragm, a rigid end member clamped thereto to pro'- vide a pressure chamber, of flexible means for reducing strains in said diaphragm due to bending thereof in proximity to said end. member. A

18. lln a pressure responsive device, theI combination with a iiexible diaphragm, a rigid end member clamped thereto to provide therewith a pressure chamber and a rigid plate secured'- to and centrally ofsaid diaphragm, of lexible gaskets to be clamped between said diaphragm and said rigid elements for `reducing strains in @said diaphragm due to bending thereof in proximity to said elements.

19. 1n a pressure responsive device, the combinationq with a pair of rigid elements, of a flexible diaphragm clamped therebetween to provide a pressure chamber and '65 a rigid plate secured to said diaphragm centrally thereof, of resilient gaskets l clamped between said diaphragm and said rigid members respectively andV extending material distances beyond the zone of clamping'pressure for reducing strains set up in said diaphragmincident to pressure variations within said chamber.

1n witness whereof, we have hereunto subscribed our naines.v

riionxs n. BARNUM. ernennen fr. evans. 

